Process of making light bricks of blast-furnace slag.



. UUMIUSHIUNS, Liammuw COATING OR PLASTIC.

0. H. SGHOL.

PROCESS OF MAKING LIGHT BRICKS 0F BLAST FURNACE SLAG.

APPL'IOATION TILED D110. 5, 1911.

1,068,396. I Patented July 22, 1913.-

COLUMBIA PLANOGRAPH 50.,WA5Hmu'r0N. D. c.

bUlvll'uol lunu,

COATING R PLASTIC.

CARL HEINRICH SCI-10L, OF ALLENDORF, GERMANY.

PROCESS OF MAKING LIGHT BRICKS 0F BLAST-FURNACE SLAG.

To all whom 2'25 may concern:

Be it known that I, CARL HEINRICH SoHoL, a subject of the German Emperor, and residing at Allendorf, Dillkreis, Ger- 5 many, have invented a certain new and useful Improved Process of Making Light Bricks of Blast-Furnace Slag, of which the following is a specification.

My invention relates to the manufacture of light bricks and the like of blast-furnace slag.

For manufacturing light bricks and the like, 6. g. of the type of the well known Rhenish artificial tuft bricks, a filling material of great volume but small density is used which is converted by a suitable binder into a plastic mass from which bricks, slabs and the like can be made and molded by various processes.

A primary object of my invention is to provide an improved process of making such light bricks and the like by using blastfurnace slag.

It is well-known to use ranulated blastfurnace sla with an admixture oi lime lor ""makmg filElfiClill stone. The process according to my invention difiers from the well-known processes in that when using the blast-furnace slag for making light bricks I obtain both the filling material and the binder from blast-furnace slag. \Vhen the slag is granulated in the customary manner in part large, very porous and light lumps, and in part granules are formed. According to my invention these bulky but very light lumps are liberated from the granules by sitting. These lumps then form the filling material while the finely ground granules, if necessary mixed with lime. form the binder. The binder is mixed in known manner with the filling material and from this mixture bricks, molded stones, slabs and the like and, indeed, any desired bodies are made in known manner. Owing to the binder setting and hardening the finished brick or the like obtains its strength which by far exceeds that of the tuii bricks on the market at the present day.

According to this process very much greater strength can be obtained when, ac-

cording to the invention, the lumps of slag serving as filling material are provided with an envelo) ofrcement mortar whereupon they are e a or a ong 1 1f necessary 5 several days, so that the envelop composed Specification of Letters Patent.

Application filed December 5, 1911.

of the binding material completely inclos- Patented July 22, 1913.

Serial No. 664,012.

ing the lamps has time to harden; llgenmh bulky, andf c'onsequently, relatively w''ak liiinps of slag are incased, as it were,

i fi' "the slag'fllcegnent, Owing to this slag 6O cement having time to harden an outwardly very hard, but very light filling material is obtained, which when mixed with the binder forms a mass which is subsequently molded into bricks and the like. The bricks, slabs, and the like thus obtained offer, of course, a very much greater resistance to compression than known bricks of the type described above, so that they can be used for all kinds of building purposes. The same result due to incasing these lumps of slag used as filling material can also be obtained by working up these lumps of slag immediately after the granulating operation. As a rule, blast-furnace slag is led in a liquid state 7 into a reservoir of water where it is quenched and granulated. \Vhen fresh, the porous lumps of slag contain approximately 40 to 50% of water. In carrying my illYCIltlOIlr into practice the binder is added in a dust- 0 like dry state to these wet lumps of slag in the proportion of 1 part binde to 1012 parts of the )orous lum )S. lhe binder and lumps are preteralily mixed on a rotary gravity mixer in which the material is 5 mixed for about 4 to 5 minutes. During this time each lump of slag becomes covered with a fine layer of the binder, while its inner pores are s '1 mivater which subsequently gradually evaporates. These incased lumps of slag are then shot loosely onto a heap.

In order always certainly to obtain as high a percentage as possible of the bulky and loose lumps of slag to be used as filling material when granulating the blast-furnace slag, according to my invention the slag is exposed to the conjoint action ofgya terand air when being granulated. It is welll'iiidwn to conduct blast-furnace slag directly into water for granulation, and 1t is also well-known to cause com )ressed air to act on the stream of slammfiases the formation of the bulky lumps of slag is, however, more or less subject to chance. Now according to my invention water and compressed air are caused to act conyomtly on the slag in such manner that an exceedingly high percentage of the filling material is produced.

The accompanying drawing diagrammatically shows in sectional elevation one form of apparatus adapted for carrying my process into practice.

Referring to the drawing, the blast-furnace slag is supplied through the channel a into a double-walled tank Z) containing water. The bottom 0 of this tank 6 is perforated like a strainer. Compressed air is supplied through the compressed air pipe (Z into the chamber between the two walls of the tank and passes through the perforations in the bottom 0 so that the slag is exposed to the simultaneous action of water and compressed air. The air must be supplied at such a pressure that the water is prevented from entering into the chamber between the walls of the tank, and the water is constantly kept in a bubbling condition by the fine jets of air entering from below. The lumps of slag and the granules are removed from the tank in well-known manner by the elevator e. The scoops of the elevator are preferably perforated in order to allow the lifted water to flow away.

It will be understood that the described apparatus may be substituted by any other suitable device which enables the slag to be exposed to the simultaneous action of compressed air and water.

1. The hereindescribed process of making light bricks of furnace slag, which consists in conducting molten blast-furnace slag into water whereby the molten slag is formed into light bulkv h mps and into granules, in separating 1e umps from the granules by sifting, in providing the lumps with a hard coat of cement, in mixing the lumps so prepared with a binder, and in forming the mixture thus obtained into bricks.

2. The hereindescribed process of making light bricks of furnace slag, which consists in conducting molten blast-furnace slag into water whereby the molten slag is formed into light bulky lumps and into granules, in separating the lumps while yet wet from the granules by sifting, in mixing the lumps while yet wet with a dry cement capable of combining with the water in them, in allowing the coating so formed to become hard, in mixing the lumps so prepared with a binder, and in forming the mixture thus obtained into bricks.

3. The hereindescribed process of making light bricks of furnace slag, which consists in conducting molten blast-furnace slag into water whereby the molten slag is formed into light bulky lumps and into granules, in separating the lumps from the granules by sifting, in providing the lumps with a hard coat of cement, in mixing the lumps so prepared with'a binder formed of said granules after being finely ground, and in forming the mixture thus obtained into bricks.

at. The hereindescribed process of making light bricks of furnace slag, which consists in conducting molten blast-furnace slag into water whereby the molten slag is formed into light bulky lumps and into granules, in separating the lumps from the granules by sifting, in providing the lumps with a hard coat of cement, in mixing the lumps so prepared with a binder formed of said granules;

after being finely ground and an admixture of lime and in forming the mixture thus ob- Famed into bricks.

The hereindescribed process of making Copies 01 this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

